Update migration paths from 10.2 to 11.0 (#5459)

We recently introduced a set of patches to 10.2, and introduced 10.2-4
migration version. This migration version only resides on `release-10.2`
branch, and is missing on our default branch. This creates a problem
because we do not have a valid migration path from 10.2 to latest 11.0.

To remedy this issue, I copied the relevant migration files from
`release-10.2` branch, and renamed some of our migration files on
default branch to make sure we have a linear upgrade path.

src/backend/distributed/sql/citus--10.2-3--10.2-4.sql

@@ -0,0 +1,7 @@
+-- citus--10.2-3--10.2-4
+
+-- bump version to 10.2-4
+
+#include "udfs/fix_partition_shard_index_names/10.2-4.sql"
+#include "udfs/fix_all_partition_shard_index_names/10.2-4.sql"
+#include "udfs/worker_fix_partition_shard_index_names/10.2-4.sql"

src/backend/distributed/sql/citus--10.2-4--11.0-1.sql

@@ -1,11 +1,7 @@
--- citus--10.2-3--11.0-1
+-- citus--10.2-4--11.0-1
 
 -- bump version to 11.0-1
 
-#include "udfs/fix_partition_shard_index_names/11.0-1.sql"
-#include "udfs/fix_all_partition_shard_index_names/11.0-1.sql"
-#include "udfs/worker_fix_partition_shard_index_names/11.0-1.sql"
-
 DROP FUNCTION IF EXISTS pg_catalog.master_apply_delete_command(text);
 DROP FUNCTION pg_catalog.master_get_table_metadata(text);
 DROP FUNCTION pg_catalog.master_append_table_to_shard(bigint, text, text, integer);

src/backend/distributed/sql/downgrades/citus--10.2-4--10.2-3.sql

@@ -0,0 +1,5 @@
+-- citus--10.2-4--10.2-3
+
+DROP FUNCTION pg_catalog.fix_all_partition_shard_index_names();
+DROP FUNCTION pg_catalog.fix_partition_shard_index_names(regclass);
+DROP FUNCTION pg_catalog.worker_fix_partition_shard_index_names(regclass, text, text);

src/backend/distributed/sql/downgrades/citus--11.0-1--10.2-4.sql

@@ -1,8 +1,4 @@
--- citus--11.0-1--10.2-3
-
-DROP FUNCTION pg_catalog.fix_all_partition_shard_index_names();
-DROP FUNCTION pg_catalog.fix_partition_shard_index_names(regclass);
-DROP FUNCTION pg_catalog.worker_fix_partition_shard_index_names(regclass, text, text);
+-- citus--11.0-1--10.2-4
 
 CREATE FUNCTION pg_catalog.master_apply_delete_command(text)
     RETURNS integer

src/test/regress/expected/multi_extension.out

@@ -880,8 +880,8 @@ SELECT * FROM multi_extension.print_extension_changes();
 ---------------------------------------------------------------------
 (0 rows)
 
--- Test downgrade to 10.2-3 from 11.0-1
-ALTER EXTENSION citus UPDATE TO '11.0-1';
+-- Test downgrade to 10.2-3 from 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
 ALTER EXTENSION citus UPDATE TO '10.2-3';
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();
@@ -889,18 +889,34 @@ SELECT * FROM multi_extension.print_extension_changes();
 ---------------------------------------------------------------------
 (0 rows)
 
+-- Snapshot of state at 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object |                              current_object
+---------------------------------------------------------------------
+                 | function fix_all_partition_shard_index_names() SETOF regclass
+                 | function fix_partition_shard_index_names(regclass) void
+                 | function worker_fix_partition_shard_index_names(regclass,text,text) void
+(3 rows)
+
+-- Test downgrade to 10.2-4 from 11.0-1
+ALTER EXTENSION citus UPDATE TO '11.0-1';
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+ previous_object | current_object
+---------------------------------------------------------------------
+(0 rows)
+
 -- Snapshot of state at 11.0-1
 ALTER EXTENSION citus UPDATE TO '11.0-1';
 SELECT * FROM multi_extension.print_extension_changes();
-                           previous_object                            |                              current_object
+                           previous_object                            | current_object
 ---------------------------------------------------------------------
  function master_append_table_to_shard(bigint,text,text,integer) real |
  function master_apply_delete_command(text) integer                   |
  function master_get_table_metadata(text) record                      |
-                                                                      | function fix_all_partition_shard_index_names() SETOF regclass
-                                                                      | function fix_partition_shard_index_names(regclass) void
-                                                                      | function worker_fix_partition_shard_index_names(regclass,text,text) void
-(6 rows)
+(3 rows)
 
 DROP TABLE multi_extension.prev_objects, multi_extension.extension_diff;
 -- show running version

src/test/regress/sql/multi_extension.sql

@@ -366,12 +366,22 @@ SELECT * FROM multi_extension.print_extension_changes();
 ALTER EXTENSION citus UPDATE TO '10.2-3';
 SELECT * FROM multi_extension.print_extension_changes();
 
--- Test downgrade to 10.2-3 from 11.0-1
-ALTER EXTENSION citus UPDATE TO '11.0-1';
+-- Test downgrade to 10.2-3 from 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
 ALTER EXTENSION citus UPDATE TO '10.2-3';
 -- Should be empty result since upgrade+downgrade should be a no-op
 SELECT * FROM multi_extension.print_extension_changes();
 
+-- Snapshot of state at 10.2-4
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+SELECT * FROM multi_extension.print_extension_changes();
+
+-- Test downgrade to 10.2-4 from 11.0-1
+ALTER EXTENSION citus UPDATE TO '11.0-1';
+ALTER EXTENSION citus UPDATE TO '10.2-4';
+-- Should be empty result since upgrade+downgrade should be a no-op
+SELECT * FROM multi_extension.print_extension_changes();
+
 -- Snapshot of state at 11.0-1
 ALTER EXTENSION citus UPDATE TO '11.0-1';
 SELECT * FROM multi_extension.print_extension_changes();